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Discussion Starter #1
Hello,
My 84 ELKY is stock with a 305 v8, TH250 tranny and 2.41 rear end. A reputable mechanic is building me a 350, 30 over, heads with 2.02 intake and 1.6o exhaust, mild cam and edelbrock EGR intake. I am using the stock quadrajet with EGR. I am going to use the stock 305 exhaust manifolds and cat for now as the car has to pass California smog.
How much HP gain will I see with this new motor?
How will the stock driveline behave with this motor? I have heard that the TH250 is not the best tranny but I don't plan to abuse the car. I want to add a posi. Will I have to change the rear end gear? All I see are posi units for 3.73 and numerically higher gears.
What do you all think?
RTT:beer:
 

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Well you will have some! Manifolds are more for torque than HP, headers are for HP. I would say at least 280-310 HP
 

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the 250 is a decent trans as long as you dont beat on it. it should run pretty good but you will need to richen the carb for the bigger motor and adjust the tps when you get it all set up. to get the most out of it legally get a chip for the 350 and have the carb recalibrated.the manifolds and cat are the same so no need to change them. the 241 gears will hurt the performance and put a lot more torque on the 250 trans.talk to trany mike on upgrades to the trans to make it live as long as posible
 

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Gonna be a one leg wonder for sure at least go for a 350 gear ratio and a true trac or you'll be eating right rears like biscuits
 

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there are 2 differant series carriers for our elcos. 2 series are for 308 and down and 3 serries for 323 and up there are plenty around for each. for a non overdrive trans i wouldnt run more than 323 gears.
 

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A 350 with a 3 speed and stock gears is not any fun unless your trying set a lsr ha-ha a set of gears are cheap so you could try a couple different set ups
 

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Discussion Starter #7
Where would be a good place to get an ECM chip for a 1984 350 non TBI? Been looking on Ebay without much luck.
RTT:smileyb:
 

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one of the advertisers here offers chips i would look for thier banner at the top of the page for it and call them as the factory chips are drieing up
 

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VINTAGE MOTORHEAD
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When you step on the "go pedal" something will actually happen. Sounds like a nice upgrade. Headers would be nice even if they sre a pain to deal with. Good luck w:beer:ith it.
 
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